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Soloha48 [4]
3 years ago
8

What is the sign of enthalpy change for (a), an endothermic reaction? (b). an exothermic reaction?

Chemistry
1 answer:
fenix001 [56]3 years ago
8 0

Answer:

The answer is: (a) positive; (b) negative.

Explanation:

The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.

a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.

b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.

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A can contains a gas with a volume of 86 mL at 30oC. What is the volume in the can if it is heated to 65oC?
Ber [7]

Answer:

New volume of gas = 95.93 ml (Approx)

Explanation:

Given:

Old volume of gas = 86 ml

Old temperature = 30°C = 30 + 273 = 303 K

New temperature = 65°C = 65 + 273 = 338 K

Find:

New volume of gas

Computation:

V1T2 = V2T1

(86)(338) = (V2)(303)

New volume of gas = 95.93 ml (Approx)

8 0
3 years ago
When a redox reaction that takes place in an acidic solution involves an oxygen imbalance, oxygen should be balanced by adding _
olya-2409 [2.1K]

Balancing redox reactions:

Oxygen should be balanced by adding H_{2}O  as needed, while hydrogen should be balanced by adding H^{+}.

What is a redox reaction?

Redox reactions, also known as oxidation-reduction reactions, involve the simultaneous oxidation and reduction of two different reactants.

The Half-Equation Method is one technique used to balance redox processes. The equation is divided into two half-equations using this technique: one for oxidation and one for reduction.

By changing the coefficients and adding H_{2}O, H^{+}, and e^{-} in that order, each reaction is brought into equilibrium:

  1. By putting the right number of water (H_{2}O) molecules on the other side of the equation, the oxygen atoms are brought into balance.
  2. By adding H^{+} ions to the opposing side of the equation, one can balance the hydrogen atoms (including those added in step 2 to balance the oxygen atom).
  3. Total the fees for each side. Add enough electrons (e^{-}) to the more positive side to make them equal. (As a general rule, e^{-} and  H^{+}are nearly always on the same side.)
  4. The e^{-} on either side must be made equal; if not, they must be multiplied by the lowest common multiple (LCM) in order to make them equal.
  5. One balanced equation is created by adding the two half-equations and canceling out the electrons. Additionally, common terms should be eliminated.
  6. Now that the equation has been verified, it can be balanced.

Learn more about redox reaction here,

brainly.com/question/20068208

#SPJ4

7 0
2 years ago
What is the change in temperature when 75 grams of water releases -2657 J of energy? The specific heat of water is 4.18 J/g°C
Naily [24]
I think the answer for this is 4702.5 J/g*k Depending on if it is water as a solid liquid or gas. I used water as a liquid when I solved it. J=(75g)(4.18 J/g*k)(15K)
8 0
3 years ago
HELP ME OMG WHY IS NOBODY HELPING ME SJCNEOVKRM
Sholpan [36]

I believe it would be CS and GE (option 3). i hope i helped ya out.

3 0
4 years ago
How much heat energy is required to raise the temperature of 5 kilograms of coal from 20c to 220c?
Elenna [48]
1.3 kJ/kg K x 5 kg x 200C = 1300 kJ 
The answer is <span>1,314,718 J</span>
7 0
3 years ago
Read 2 more answers
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